LSX Engine Build - The Future Of Chevy Performance Is Here

The Inside Story On How GMPP Built The World's First LSX-Based Engine

In September 2006, Reggie Jackson was flown to WJ Enterprises, where "The Professor" helped "Mr. October" assemble the world's first LSX block-based engine. The team of engine assemblers consisted of (left to right) GMPP Engineer Shawn Johnson, Reggie Jackson, Warren Johnson, and GMPP Marketing Specialist Thomas Bates. The final configuration was a 454-inch LSX small-block that cranked out 641 hp and 611 lb-ft of torque. As you can tell, the two great champions of their respective sports were more than a little proud of their accomplishment.

The Reggie Jackson '69 Camaro debuted at the 2006 Las Vegas SEMA trade show with all of the subtlety of a 500-foot home run blast. Bright red in color with a slammed, pro-touring stance, the car oozed power, muscle, and performance-some of the same attributes that helped its owner have a Hall of Fame major league baseball career. And, underneath all of those trimmings lies the main reason this car is so special: the first application of GM Performance Parts' new, ground breaking LSX Bow Tie block.

The amazingly efficient 454-inch LSX-blocked engine in Reggie's car cranks out over 640 hp and 610 lb-ft of torque from pump gas. Besides the LSX block, several one-off and hand-fabricated pieces had to fall into place before the ignition could be fired on this new generation Chevy engine. This is the story of how the first LSX engine was designed, assembled, and brought to life by GM Performance Parts.

There is no question that General Motor's LS family of engines has redefined efficiency and performance from a small-block, pushrod V-8. The 400hp factory offerings have been no problem for LS1 LS6 and LS2 configurations, and with the amazing LS7 (as found in the current production ZO6 Corvette-the fastest factory Chevrolet Corvette ever sold to the public) the 500hp plateau has been bridged.

In the aftermarket, serious drag racing, road racing, and street car efforts have taken factory aluminum LS blocks well beyond the 1,000hp level. But that has come with exotic fasteners, very expensive machining procedures, and a borrowed life expectancy.

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The Hot Rod TV crew tapes the action as Bates details the features of the LSX block to Jackson, while co-designer Johnson makes sure Bates' info is correct. The LSX Bow Tie block offers 6-bolt mains, six bolts per cylinder, reinforced main webs and deck, a true priority main oiling system, and a low street price for a block designed to hold over 2,000 hp.

The aftermarket has countered with some truly impressive pieces. High-end LS blocks like GM Racing's C5R Corvette block have allowed big power LS engines to function flawlessly past 1,000 hp. About the only downside to the aftermarket solution of high-performance aluminum LS blocks is the cost. Often, bare-aluminum "high-end LS" blocks can cost over $5,000. And, while that will certainly work, it goes against the low-buck, high-efficiency design that the LS family of engines has defined for over a decade.

Enter GM Performance Parts. In late 2005, its marketing and engineering staff began the process of designing a better LS block. The goals were simple: Allow big-time, race-car applications for the street or track, while keeping the cost as low as possible. To do this, the team enlisted the help of Warren "The Professor" Johnson, their six-time NHRA Pro Stock drag racing champion, and a man who knows a thing or two about what makes a great race block. Starting with the math data of the 6-bolt main LS7 427-inch block, GM Performance Parts and WJ started tweaking things. First, the decision was made to go with cast iron as a material. This would keep the cost low, the machining costs down, add an incredible amount of strength to the finished project, and allow for a massive bore size for naturally aspirated engine combinations.

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Here's a close-up of LSX Bow Tie block No. 1. For this build, GM Performance Parts drew up a 4.185-inch bore with a 4.125-inch stroke crank for the magic 454ci combination. It also shows how you can get a 454 without a 4.250-inch stroke so that characteristics of this engine are much more car-like (higher rpm potential) than truck-like (limited top end with good low-end grunt). The final engine has a 7000-rpm redline with more than ample torque at 2500-3500 rpm.

In addition, looking into the future use of the LSX block (PN 19166454), one can appreciate that the same block can quite literally grow with the owner as his/her needs expand. If the block were to get wounded in a racing effort, just have it machined/honed for the next-sized piston. No elaborate sleeving of the block would be needed. Additional material has been added to the deck surfaces, main web areas, siamesed bore, and oil pan rail.

For those interested in big nitrous systems, large superchargers, or twin turbocharging, the LSX is the block for you. One of the most groundbreaking features is the six-bolt-per-cylinder design. An additional fifth and sixth head bolt have been added to increase the clamping force of the head onto the block's deck surface so that high compression applications (such as 45-plus psi of boost from a forced induction combination) doesn't literally lift the head off the block. According to GM Performance Parts: "The additional fifth and sixth head bolt holes have been added for boosted and high-compression engines. All six bolts per cylinder are on the same bolt diameter for better gasket sealing and clamping."

Other attributes of the factory LS7 block were left in place such as the bay-to-bay breathing design. This release of crank case pressures from one cylinder to the next was worth over 35 hp in the production 505hp LS7, while costing nothing in structural rigidity. One can only imagine what it will be worth to the 2,000hp engine combinations that are being planned for the LSX Bow Tie block.

In its final form, the LSX offers the potential for a massive 4.25-inch max bore that allows for 482ci from a small-block LSX engine using the max stroke. And, with the forthcoming tall-deck version (9.7-inch deck height), you are looking at 510ci small-blocks.

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The Lunati crankshaft has already been dropped into position, and Jackson is bolting down the 6-bolt mains with ARP fasteners. Notice that "The Professor" keeps an eye on "Mr. October" to make sure he takes very good care of the very first LSX Bow Tie block.

The concept of teaming up with Reggie Jackson to build a SEMA vehicle initiated in May 2006. GM Performance Parts was looking for a '69 Camaro to showcase an engine built from its new block. The Camaro would be given an "evolution" treatment: modern suspension and brakes, updated interior, paint code from the amazingly successful '09 Concept Camaro, and styling touches that matched its owner's personality and taste. We'll let you decide how the final car turned out (see the preceding story), but the engine had to match those same goals.

Once Reggie agreed to let GM Performance Parts "borrow" a '69 Camaro from his collection, the GM Design Center and GM Performance Division teams went to work, while GM Performance parts started drafting what would become the first ever application for their new LSX Bow Tie block.

Reggie loves big-blocks, as one can tell by the collections of cars that surround him. Every first generation Camaro that he owns either says COPO, ZL1, Yenko, Motion, or simply "427" on the side of it. It was clear that the LSX engine would have to exude the same qualities that the '60s big-block musclecars had. In other words, torque was going to be the name of the game with this promising small-block effort.

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Jackson flips the LSX block over for installation of the Lunati rods and Mahle pistons.

GM Performance Parts Marketing Specialist Thomas Bates was assigned with the task of designing the LSX-based engine for the Reggie Jackson '69 Camaro. And, with the build climaxing in a test session for Hot Rod TV at GM's Milford Proving Grounds, this was going to be a car that was going to be driven with passion, not just rolled onto the SEMA show floor. Focusing on offering enhanced low-end torque with high-rpm potential, the LS family of engines is a natural for this application.

With the LSX block as the foundation, Bates whipped up a 4.185-inch bore and 4.125-inch stroke combination for nice Chevy-sounding 454 inches. Again, that's from a small-block. The rotating assembly consists of a forged Lunati crank with 6-inch Lunati forged steel rods and reverse-domed Mahle pistons for a pump-gas friendly 11.0:1 compression.

The custom Crane cam specs out at 236 @ .050 on the intake and 246 @ .050 on the exhaust with .630-inch lift on the intake and exhaust with a 110-degree lobe separation. Working with stock LS7 roller rockers (1.8:1) ratio, titanium LS7 intake valves (2.200-inch) and sodium-filled exhaust valves (1.61-inch), the LSX prototype heads flow 360 cfm on the intake at .700-inch lift. Together, this high-tech valvetrain helped the LSX 454 obtain an easy 7000-rpm red line.

The custom Crane camshaft has already been installed here. The cam cover is provided with every LSX block. The cam specs out at 236 @ .050 on the intake and 246 @ .050 on the exhaust with .630-inch lift on the intake and exhaust with a 110-degree lobe separation.

As part of the Hot Rod TV show, GM Performance Parts had invited Jackson to fly to Sugar Hills, Georgia, home of WJ Enterprises, to assemble the first LSX engine with Warren Johnson. Both Reggie and WJ had been looking forward to this day since the project began. And, although the two had never met in person until this date, they quickly became an "LSX Engine Assembly" team. For the most part, Reggie did all of the wrenching on his engine as WJ passed him parts and tools while making sure that Reggie was putting the engine together exactly as he should.

On September 12, 2006, at about 5:00 p.m., Reggie placed the Holley carburetor onto the GM Racing LS7 carbureted intake and proclaimed that the 454 LSX engine was ready for the dyno. Kurt Johnson had prepped the dyno room-an extension of his office in the family's race shop-for the small-block. It was the first time in 15 years that an engine other than a Warren Johnson 500-inch NHRA Pro Stock engine was going to spin the dyno at WJ Enterprises.

After some minor carb tuning, Kurt pulled the throttle block and the LSX Design Team celebrated with a 641hp, 610-lb-ft pull of the dyno. At only 3000 rpm, the LSX 454 was already kicking out over 520 lb-ft of torque, more than most factory big-blocks could ever muster. Reggie congratulated the team members and thanked them for the hard work.

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Here's a close-up of the piston and rod combination for the 454 LSX engine. It consists of a 6.00-inch forged Lunati rod and a Mahle piston. The piston is technically called a 13cc reverse dome design that results in a final static compression ratio of 11.0:1 when combined with the prototype LSX heads.

Awaiting the finished engine was Al Oppenheiser, Mike Copeland, and the GM Performance Division back in Milford, Michigan. With only six weeks to completely restore, assemble, calibrate, and safety-check Reggie's '69 Camaro, they were anxiously awaiting the crate full of the assembled LSX engine. Once installed in the Camaro, GM Performance Parts would once again call on Reggie to test its new engine in a platform that he was very familiar with.

It almost seems too easy, doesn't it? The secret to a 600-plus horsepower small-block (with all of the manners of a stocker) lies in the advanced engineering and efficiency that GM Powertrain has designed into every LS engine. The LSX Bow Tie block just lets you take all of this to an extreme level. With an MSRP of $2,500 and a street price of around $1,900, the LSX block is a piece of equipment that you can get into now and build up over time, using the components that you have on hand-replacing them as you increase the capabilities of your combination.

GM Performance Parts has enjoyed so much success with the Reggie Jackson '69 Camaro, and the LSX 454 crate engine in it, that it is planning on offering the LSX 454 as a stand alone crate engine in late 2007. Of course, there are also plans to expand into an entire crate engine portfolio based on this block. As for the LSX Bow Tie block itself, it goes on sale nationwide on March 31 this year.